What are the requirements for traveling to Canada by land for Non-US citizens (permandent residents)?

I know for US citizens, to get into Canada by land, all you need is a passport or something to prove your citizenship. However, what exactly are the requirements for non-US citizens? Is a green card sufficient?
In response to the first answer, I'm more interested in weekend vacation.

depends on what ur intentions are.. if just travelling or wanting to immigrate.. and depending on country ur comin from.. here's some links u can check into.. maybe can get all info you need on here.. best of luck.. www.cic.gc.ca
www,stepbystepimmigrationcanada.com
www.canadaimmigrationlaw.net

If you are a US or Canadian citizen and are travelling by land, you need:
- proof of citizenship (passport or birth certificate)
- valid photo ID (passport, driver's license, or military ID)

If you are NOT a citizen of either country, you MUST have a passport to travel across the border (in either direction). This is for the 'proof of citizenship' requirement, mainly, but also happens to be valid photo ID. In your case, the reason for this is that a permanent resident is NOT a citizen - and everyone must be a citizen of SOME country.

In addition, if you must also be abel to provide (on demand, at the border point) the documentation regarding your residency status (i.e. green card for the US, or PR card for Canada), and - if a naturalized citizen - the documentation reflecting that as well.

Work visa status, I-94s, etc are also required ... and should be included in your passport anyway.

no, well doesn't matter how much time u want to go, even if your trip is for a weekend u'll need a visa, (depending on your country) what is country?? if u live in some of the countries where u don't need visa, u just need a passport, if u live in some other country*, http://www.cic.gc.ca/english/visit/visas.html if u live in those countries u need visa, (there's the list in the link), if u don't like i said u need a passport, money, and u'll be free, if u DO need visa, in the same link u'll find the process to get one, to live as a permanent resident : http://www.cic.gc.ca/english/faq/resident-1.html check that site, hope my info help ya, and have a nice trip enjoy canada. ciao.